SMT6 cracked/broken...should I stick w/ this?

[kinkyllama]

So that seams to be the problem with my engine not reving above 4k rpm. It's really strange because it wasn't in a place where anything could have hit it and cracked it...and the cable to go to the PC disappeared. Anyway my engine seams to lean out at 4k rpm, without the SMT plugged in it runs really rich untill 5k rpm then leans out but will rev to 6k.

Anyway, I contacted SMT to see if it's possible to fix but if not I'm woundering if I should go with something different. I really really want to raise the RPM limit, not for power but for other reasons but a stand alone is kind of out of my budget. Is there any other way to raise the rev limiter? Does anyone know if the SMT-7 wires up the same as the SMT-6, I'd like to just be able to plug it in where the SMT6 was or is it even worth getting the SMT7 over the SMT6?

Thanks guys,
Danny

[Efratech]

tbh, with you going for a turbo soon, i will go full standalone

[kinkyllama]

tbh, with you going for a turbo soon, i will go full standalone

That's doable...depending on how much it would cost to have installed. Any idea?

I could cough up the money for a stand alone, but I'm not sure about installation. I still gotta build my tubular turbo manifold, turbo exhaust, and a few other bits.

[Efratech]

why dont you look for AEM for example,

i guess you first should contact AEM and ask a provider in your area, them check with them

a good shop can make you a nice wiring loom

[exist3nce]

Did you get the wideband installed to verify where its rich / lean?

As I mentioned before, I don't think any piggybacks can change rev limiter. Typical way of doing this is with chipping the ecu or reflashing.

For piggyback alternatives I have no experience with the SMT series, but I would recommend Emanage (preferably the ultimate) or the AEM FIC.

If you know what you are doing with tuning and wiring a standalone is doable, but it is much more involved than wiring and tuning a piggyback. If you want the absolute highest degree of "tunability" and most features for your motor, this option is for you.

[PrecisionBoost]

Man you have the worst luck of anyone I know

Seriously.... where did BMS mount the SMT6 that it managed to get damaged like that?

As far as the redline.... why would you want to raise it?

Unless your planning on some serious engine work such as milling/porting the head, replacing valvetrain components and balancing/upgrading your bottom end it would be a waist of time and dangerous.

The power drops like a rocknear redline because the stock intake runners in the cylinder head are choking things off.


For a naturally aspirated vehicle you do want a high redline, but for turbo engine it makes no sense to go through all that work

If this is an issue with the speed in each gear then you would be better off having the final drive on the F28 replaced... I'm sure it would be cheaper in the long run.


If you allready have the SMT6 wired in then there is no reason to upgrade to a different Piggyback system.... you should be able to pick up a used SMT6 for cheap ( $100 ) if you wait a bit.... especially if you find one without a wiring harness.


Don't go standalone.... it will be 2009 before you have it back on the track!

The cost of a standalone is the small portion of the total bill...... tuning a standalone from scratch takes lots of time and can cost thousands for all the dyno time.

If you were planning to run 600whp.... then yes.... a standalone might be in order.... but from what I gather your not looking to go that high (obviously a stock engine won't even come close to that)

[exist3nce]

Man you have the worst luck of anyone I know

Seriously.... where did BMS mount the SMT6 that it managed to get damaged like that?

They mounted it in his engine bay!!

[kinkyllama]

As far as the redline.... why would you want to raise it?

Unless your planning on some serious engine work such as milling/porting the head, replacing valvetrain components and balancing/upgrading your bottom end it would be a waist of time and dangerous.

The power drops like a rocknear redline because the stock intake runners in the cylinder head are choking things off.


For a naturally aspirated vehicle you do want a high redline, but for turbo engine it makes no sense to go through all that work

If this is an issue with the speed in each gear then you would be better off having the final drive on the F28 replaced... I'm sure it would be cheaper in the long run.


If you allready have the SMT6 wired in then there is no reason to upgrade to a different Piggyback system.... you should be able to pick up a used SMT6 for cheap ( $100 ) if you wait a bit.... especially if you find one without a wiring harness.


Don't go standalone.... it will be 2009 before you have it back on the track!

The cost of a standalone is the small portion of the total bill...... tuning a standalone from scratch takes lots of time and can cost thousands for all the dyno time.

If you were planning to run 600whp.... then yes.... a standalone might be in order.... but from what I gather your not looking to go that high (obviously a stock engine won't even come close to that)

I'd like to raise it for one so I can hit 60mph in 2nd gear just for more impressive times/bragging rights. The biggest advantage would be for the road courses, I like the gearing the way it is but it doesn't work for every track and corner. There plently of times I'll stay at 6450rpms because the corners to close to shift up but I could still get a decent amount of speed in if I had more RPMs....also speaking of which I shift easy/slow unless I'm drag racing or really trying to get good times. I was under the impression my rods/pistons were safe up to 7,200rpm but now I wounder if I got that mixed up with something else cause I can't find anywhere where Tom told me that. I think I could mill/port the head for really cheap though cause I'm friends with some guys at a machine shop, but other than higher RPMs would I see any gains?

Is there anything I can have done to my pistons/rods to handle more power? Here's what's already done:
"New Mahle C20LET, stock compression, std size. With rings, pins and clips. Tops are ceramic coated, while skirts are molybdenum coated. Pistons are balanced to 440 grams each.
New rods, debeamed and polished. Big end and small ends were resized. Rods come with ARP ProWave 2000 bolts and ARP Moly. Rods were balanced to 677 grams each."

I will probably run near the safe limit for them of 350 crank hp, but I'll have to beef up my F28 slightly (cause of my 235 toyo RA-1s) and am thinking since the F28 will be able to handle allot more I should do something with my internals before installing them incase I end up craving more.

Any ideas where to find the SMT used other than eBay? It's really strange what regions it's popular and not even known in. I was qouted $360 for a new SMT6 without harness, hopefully the SMT7 can hook up to the same harness and if so I'll go with that.

Can the SMT be tuned to adjust boost pressure for different RPM ranges?

Also is there any way without a piggy back to raise the rev limit?

Lastly, anyway to bypass my SMT-6 or is unplugging it just do that? Without it I'm running rich, esp at higher rpm...so I first assumed the SMT was still effecting it but then I remembered I have the upgraded fuel pump.

Man you have the worst luck of anyone I know

Seriously.... where did BMS mount the SMT6 that it managed to get damaged like that?

They mounted it in his engine bay!!

+1. Strange thing is I still don't understand how it got cracked, and so badly (one whole side is cracked badly, plus some). It wasn't anywhere where it could have gotten hit, knocked, or pinned between things. Also my comms cable disappeared.... I kinda wounder if a shop that didn't like me screwed it up.

The widebands installed I just don't have the bung for it. My buddy can do it in no time but I'm waiting till he has more time so we can start on strut braces cause it's little bit of a drive. Since I know my SMT is screwed up I'm not as concerned with AFR untill I get a new SMT.

[daewoomofo]

i wouldnt be suprises if your piggyback got cracked when they did the f28 swap.

[PrecisionBoost]

I would never recommend installing a piggyback like that in the engine bay.... I realize that the ECU is in the engine bay but that is no excuse.

When I installed my SAFC I found it extreemly easy to pull wires in past the firewall on the drivers side (between the inner and outer fenders near the top.... there is a direct opening into the car down on the bottom left side.

If it's going into the engine bay I would allways suggest a NEMA aluminum case (waterproof and shock proof) they aren't expensive ( usually around $20 for that size)

I didn't know what you had in store for the engine.... with the rods and pistons I'd guess 7K is possible.... I wouldn't go past that due to the fact that you might get some valve float issues.

Given the lower compression C20LET pistons it might not be such a big issue.... but if I were you and I had the head out to get opened up I would replace the valve springs with something stronger.

Once you have stronger valvesprings I'd say that 7500RPM should be fine..... I do stress the word "should be"

Personally if I had all that work being done I would have the entire engine assembly balanced.... which would again help out with the redline.


If you plan to make 350whp you should port the head..... the stock head is not bad... but you will be sucking in nearly three times the amount of air compared to stock.

The benifit will be that your engine will be much more efficent under boost..... so you will need less boost to make 350whp than someone using a stock cylinder head with no porting.

You could look into a process called Extrude Honing...... it makes the intake ports much more efficient.... the areas causing "drag" will be removed via abrasives during the process.


As far as the SMT6..... I will see what I can dig up.... I think my cost was around $225 at one point last year when I was looking at picking one up.... if I give up the harness it might be even cheaper (since they can sell the harness for a fair bit of money )

[GsiTurbo]

Sorry to hear about the cracked SMT-6 Danny....this really, really sucks. Seems that lately if it is not one thing with the car, its another

To answer your question about the rpm range, I would stick to the 7000rpm range. Even with extensive cylinder head work, in terms of improving the volumetric efficiency, you would need a monster turbocharger to keep the motor in the power-band at such high rpm. This is doable, don't get me wrong, but it would cost you every-day drivablity due to turbo lag. Realistically speaking, with proper-sized turbocharger, the motor will be out of power-band by about 6000rpm or so. So in a real-life driving, there would really not be any reason to rev it higher, as when you shift onto the next gear, you would have a little of powerband left. Hence, the acceleration would suffer.

Besides, without having the entire motor perfectly re-balanced, chances are something may go wrong causing serious motor damage. Even with the GSI build-up, while theoretically I can be revved to 8500 rpm (due to ligthweight steel rods, super light wiseco pistons and lighter flywheel), chances are there would be no sense in doing so. I would keep the rpm to 7000rpm, with a 'buffer zone" of another 400rpm, but no more. These pistons will take a lot of beating, but the higher the boost (above 15psi), the more stress they will see at higher rpm. If you plan to run 20psi, I would back off the redline by 200-300rpm or so. Then, you can take full advantage of the extra gearing you have in your F28. For comparison, the GSI has no traction till the 4th gear (no LSD)...but then the entire hell breaks loose and it goes like it runs on a diced lions.

You must get aftermarket valvesprings... dual set from QED works excellent and its worth every penny (if I recall, I paid $230 or so for set of 16 dual springs and 16 special spring seats). If you want more weight reduction in the valvetrain, see if QED can supply titanium spring retainers. Remember, one must look after not only the bottom-end, but also top end for safe high rpm.

My 5 cents.
Tom

[kinkyllama]

Thank you for the info guys.

Hey Tom any chance the internals I got from you can handle more hp safely? Or is there anything left I can do to them so that they can?

Is tq the killer of internals as well or is hp & tq pretty even at that point?

I'm probably going to go with the SMT-7 if I can make it work with the same harness, the perfect power tech guys say they're different but I might be able to get it to work--still waiting the final word from them. As easy as the installation of the SMT units are, and the fact I'm getting decent with wiring I might go with the SMT-7 either way. There are several functions that the SMT7 has but not the 6 that I think would be helpfull.

Is there any way I can raise the rev limiter without a full stand alone?

Last thing, can the SMT adjust boost with RPMs (i.e. run less boost above 6.5k) or is that a boost controller thing? The SMT7 has some kind of boost control but I can't tell if it'd do exactly what I'd like...which is trying to get as even of power levels across the RPM range untill 6.5k RPM then dropping it down a bit for safety.

Danny

[PrecisionBoost]

The C20LET pistons and rods should be nice safe for 300whp.... could you take it to 350whp??? Yes probably.... but I don't think you will be able to put that much power down to the ground even with the F28, LSD and RA-1's

With pistons and rods I would say it's "horsepower" that determines when things break.... since both torque and RPM will be the main factors and horsepower is simply (Torque X RPM ) / 5252 you can see that raising either one will increase load on the engine components.

For gearboxes were talking about torque as the limiting factor.... RPM doesn't affect the internals the same way it does the engine components.

Basicly in a transmission all the components are circular gears being loaded on the outside edges..... they really aren't loaded that much more by increasing RPM....only the bearings see additional stress from higher RPM.

That's why lots of the high horsepower engines make their power way up around 10,000 RPM..... that way the torque is low enough not to kill the gearbox

If your making 350lbft of torque at the wheels at 10,000 RPM then we can calculate the horsepower as ( 350 )(10000) / 5252 = 666 whp


Basicly there are two kinds of loads on the engine components..... the first is the raw force produced by burning the Air/fuel you've pushed into the cylinder.

The second force is created on the piston pin, connecting rod, crankshaft and bearings as the piston accelerates up from BDC and the quickly decelerates to TDC (where it's almost not moving at all )

The forces on the parts are directly related to the acceleration and deceleration...... so higher RPM means that the forces will go up (with the square of the difference in fact)

Hopefully you get what I'm saying here.

Running 350whp puts stress on the components but it fails to compare with the added stress created by increasing the RPM by a few thousand.


Personally with the stuff you have..... I would set things up for about 325whp and 300lbft with a stock redline.


When it comes right down to it the only true way to get rid of the rev limiter is to reburn the ECU

Faking out the ECU is a major task since it uses the crankshaft reluctor wheel to calculate fueling and I'm pretty sure that's where it gets it's RPM value from..... both the Cranshaft reluctor sensor and camshaft sensor would have to be "hacked" by a fairly complex microcontroller program.

When you hack the signal it would keep the ECU from seeing higher RPM but it also stops the ECU from throwing out more fuel to accomidate for more air coming into the engine (since RPM and air intake volume are directly related)

This causes a major lean out and I have to think most Piggyback units are unable to accomidate such a large difference in fuel requirements.

If you had a retrurn fuel system you could throw in a rising rate fuel pressure regulator to help out... but it's definitly going to cause some issues.

Personally.... I think that increasing the redline requires a pile of work.

If your super serious about it then you really need to talk to Chip at BMS and see if they can reprogram your ECU ( I think he said once that he has that ability..... but don't quote me on that )

The next best option is a standalone or moving to a different engine management system like Efrain did.

Standalones are a pain to setup most of the time.... especially on an engine that's never been programmed before.

If you had a Mitsu or something like that it would be easy to simply search around and get the initial programming data from someone who's willing to give you the BIN file.

But with an engine like the U20SED there is no help out there..... and most shops will take weeks to get the car running.


There is no real simple solution to increasing the Redline..... I don't know what else to tell you.

[Efratech]

theres a myth on the C20LET rods being on the limit at those numbers.

But the bristish don't seem to know the true limits

tbh i dont think an standalone is that much hassle, my ecu is honda but mainly is an standalone. had to be mapped almost from scratch using a b18 base map (totally different engine) and only had to add enough fuel and some timing to get it idle and with a good enough AFR to break the engine in.

should be "easy" by using a similar 2.0 (SR20, K20, 3SGTE) base map and start from there

[kinkyllama]

The C20LET pistons and rods should be nice safe for 300whp.... could you take it to 350whp??? Yes probably.... but I don't think you will be able to put that much power down to the ground even with the F28, LSD and RA-1's

With pistons and rods I would say it's "horsepower" that determines when things break.... since both torque and RPM will be the main factors and horsepower is simply (Torque X RPM ) / 5252 you can see that raising either one will increase load on the engine components.

For gearboxes were talking about torque as the limiting factor.... RPM doesn't affect the internals the same way it does the engine components.

Basicly in a transmission all the components are circular gears being loaded on the outside edges..... they really aren't loaded that much more by increasing RPM....only the bearings see additional stress from higher RPM.

That's why lots of the high horsepower engines make their power way up around 10,000 RPM..... that way the torque is low enough not to kill the gearbox

If your making 350lbft of torque at the wheels at 10,000 RPM then we can calculate the horsepower as ( 350 )(10000) / 5252 = 666 whp


Basicly there are two kinds of loads on the engine components..... the first is the raw force produced by burning the Air/fuel you've pushed into the cylinder.

The second force is created on the piston pin, connecting rod, crankshaft and bearings as the piston accelerates up from BDC and the quickly decelerates to TDC (where it's almost not moving at all )

The forces on the parts are directly related to the acceleration and deceleration...... so higher RPM means that the forces will go up (with the square of the difference in fact)

Hopefully you get what I'm saying here.

Running 350whp puts stress on the components but it fails to compare with the added stress created by increasing the RPM by a few thousand.


Personally with the stuff you have..... I would set things up for about 325whp and 300lbft with a stock redline.


When it comes right down to it the only true way to get rid of the rev limiter is to reburn the ECU

Faking out the ECU is a major task since it uses the crankshaft reluctor wheel to calculate fueling and I'm pretty sure that's where it gets it's RPM value from..... both the Cranshaft reluctor sensor and camshaft sensor would have to be "hacked" by a fairly complex microcontroller program.

When you hack the signal it would keep the ECU from seeing higher RPM but it also stops the ECU from throwing out more fuel to accomidate for more air coming into the engine (since RPM and air intake volume are directly related)

This causes a major lean out and I have to think most Piggyback units are unable to accomidate such a large difference in fuel requirements.

If you had a retrurn fuel system you could throw in a rising rate fuel pressure regulator to help out... but it's definitly going to cause some issues.

Personally.... I think that increasing the redline requires a pile of work.

If your super serious about it then you really need to talk to Chip at BMS and see if they can reprogram your ECU ( I think he said once that he has that ability..... but don't quote me on that )

The next best option is a standalone or moving to a different engine management system like Efrain did.

Standalones are a pain to setup most of the time.... especially on an engine that's never been programmed before.

If you had a Mitsu or something like that it would be easy to simply search around and get the initial programming data from someone who's willing to give you the BIN file.

But with an engine like the U20SED there is no help out there..... and most shops will take weeks to get the car running.


There is no real simple solution to increasing the Redline..... I don't know what else to tell you.

Thank you.

I'm not wanting to make more power than that right now, I just figured since they're still out I should do something to beef them up more incase I catch the boost fever.

I'll be fine with the factory redline, it's not worth much hassle to me but if BMS can do it fairly cheap/easy then I would probably do that.

Thanks Efrain

Now I just got to get ahold of an SMT7, unless I come across a used SMT6 unit.